Table 5.

Factors associated with Doubling of the Daily Opioid Dose

Variables	All Patients (N=419) Adjusted OR (95% Confidence Intervals)	P-values	Postoperative (N=210) Adjusted OR (95% Confidence Intervals)	P-values	Medical (N = 209) Adjusted OR (95% Confidence Intervals)	P-values
Age groups:		0.50		0.53		0.90
Infant (< 1 yr)	0.81 (0.37, 1.79)		0.47 (0.12, 1.79)		0.95 (0.37, 2.50)
Child (1 yr – < 10 yrs)	1.21 (0.55, 2.65)		0.69 (0.17, 2.81)		1.15 (0.45, 2.95)
Adolescent (10 yrs–< 18 yrs)	Reference		Reference		Reference
Female (vs. male)	1.10 (0.61, 1.96)	0.75	2.79 (0.99, 7.87)	0.052	0.68 (0.33, 1.40)	0.29
Baseline opioid dose (1 unit mcg/kg)	0.96 (0.95, 0.98)	<0.001	0.96 (0.94, 0.98)	0.001	0.97 (0.95, 0.99)	0.004
Primary opioid morphine (vs. fentanyl)	0.48 (0.25, 0.92)	0.03	0.27 (0.08, 0.88)	0.03	0.60 (0.27, 1.33)	0.21
Midazolam used	5.57 (2.41, 12.9)	<0.001	6.31 (1.73, 23.0)	0.005	6.91 (2.21, 21.7)	<0.001
Lorazepam used	N.S.	--	5.21 (1.49, 18.2)	0.01	N.S.	--
Opioid infusion ≥ 7 days	7.85 (4.32, 14.3)	<0.001	5.86 (2.10, 16.3)	<0.001	7.06 (3.33, 15.0)	<0.001
History of previous PICU admission	0.37 (0.15, 0.89)	0.03	N.S.	--	N.S.	--

Note that age group, sex, baseline opioid dose, and primary opioid used were included a priori in all models. Other variables were selected based on backward variable selection with a significance level of 0.05. The variable selection procedure was performed separatelyfor each of the three analyses above. The adolescent age group was used as a reference group because it is closest to adult patients. OR = odds ratio, NS = not selected in the logistic model because p>0.05.